Latch mechanism assembly for retractable ball pen



1961 J. c. LqcKwooD 3,007,444

LATCH MECHANISM ASSEMBLY FOR RETRACTABLE BALL PEN Filed June 3, 1958 3 Sheets-Sheet 1 anw:

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INVENTOR. 10!! C. LOCKWO0D 1 ATIVPIYEHS Nov. 7, 1961 J. C. LOCKWOOD LATCH MECHANISM ASSEMBLY FOR RETRACTABLE BALL PEN Filed June 5, 1958 .3 Sheets-Sheet 2 6' 2% 6'0 x g 64 "i g 66 4 7 62 16 "1 i1 INVENTOR.

BY JOHN c. wcrrwoop J. C. LOCKWOOD 3 SheetsSheet 3 .{IINVENTOR 10 C. LOCKWO0D ATTORNEYS Nov. 7, 1961' LATCH MECHANISM ASSEMBLY FOR RETRACTABLE BALL PEN Filed June 3, 1958 a 26 w e vmm i I United States Patent Ofifice 3,007,444 Patented Nov. 7, 1961 3,007,444 LATCH MECHANISM ASSEMBLY FOR RETRACTABLE BALL PEN John C. Lockwood, Atlanta, Ga., assignor to Scripto, Inc., Atlanta, Ga., a corporation of Georgia Filed June 3, 1958, Ser. No. 739,545 4 Claims. (Cl. 1'2042.03)

This invention relates to retractable ball point writing instruments, and more particularly to a novel form of latch mechanism assembly for such writing instruments incorporating the general operating characteristics disclosed and claimed in copending patent application Serial No. 631,771, filed December 31, 1956, now Patent Number 2,930,354 in which a uniquely arranged rocking latch member is provided for projecting and retracting a writing unit alternately upon successive depressions of a plunger member.

Briefly described, the latch mechanism assembly of the present invention is characterized by an interlocked arrangement of a rockable floating latch member with a depressible operating plunger therefor. The latch member is shaped, as in the above noted copending application, for sliding longitudinally and rocking transversely in opposite directions selectively upon successive depressions of the plunger member into contact therewith so as alternately to project and retract the writing unit, both the latch member and the plunger member having opposed contact surfaces arranged in alternate paired relation for operation of the latch member in the above noted manner by the plunger member.

The latch member is further arranged according to the present invention so that it is retained in operative relation with the plunger, a leg portion being formed for this purpose on the plunger to extend at a side face of the latch member and the plunger leg portion and latch member side face having respectively a relatively narrow transverse retaining lug formed on one and a relatively wide transverse groove or recess formed on the other for receiving the retaining lug and thereby interlocking the plunger and latch members in asembled operating relation. The transverse groove or recess is of such width and depth as to allow necessary operative movement of the latch member freely with respect to the plunger without bringing the retaining lug into contact with any bounding surfaces of the groove or recess, while still providing an interlocked assembly between the plunger and latch members.

By this assembly arrangement of the plunger member and latch member in freely floating interlocking relation, a number of substantial advantages are provided by the present invention. It is possible, for example, as described further below, to employ such an arrangement within a sleeve so as to form a package latch mechanism adaptable for use in writing instruments having exterior different stylings and aesthetic features, and thereby greatly simplify the design of new models and reduce the cost of manufacture thereof, since the same package mechanism for projecting and retracting the writing unit can be utilized interchangeably in different models simply by employing a uniform internal barrel form for receiving and retaining the package mechanism therein.

The components of a package mechanism such as is described above, namely, a plunger, latch member, and retaining sleeve, are readily made of molded nylon which has excellent strength and wear characteristics, and which provides contact surfaces having a low coefficient of friction that is conducive to smooth and reliable operation. Also, where a package mechanism of this sort is used a great latitude of choice is gained in the selection of the material for the writing instrument barrel since the necessary requirements for satisfactory mechanical operation in projecting and retracting the writing unit are all satistied in the package structure.

In addition, where it is desired to form the latch engaging means integrally within the bore of the barrel, it is posible to minimize the components of the latch mechanism assembly provided by the present invention to two members; namely, a plunger and a latch arranged for interlocking within the barrel so that the plunger retains the freely floating latch within said barrel when the writing unit is removed and the latch prevents removal of the plunger from the rear of the barrel.

These and other features of the present invention are described in further detail below in connection with the accompanying drawings, in which:

FIG. 1 is a central, longitudinal section of a retractable ball pen incorporating a latch mechanism assembly embodying the present invention;

FIG. 2 is an exploded elevation of the several components forming the retractable ball pen shown in FIG. 1;

FIG. 3 is an exploded perspective view of the components forming the latch mechanism assembly as seen in FIG. 1;

FIG. 4 is a partial longitudinal section corresponding generally with FIG. 1, but rotated with respect thereto, and showing the latch mechanism assembly at retracted position;

FIG. 5 is a corresponding partial longitudinal section showing the latch mechanism assembly during movement to projected position;

FIG. 6 is a corresponding partial longitudinal section showing the latch mechanism assembly engaged at projected position;

FIG. 7 is a corresponding partial longitudinal section showing the latch mechanism assembly disengaged at projected position in preparation for retraction;

FIG. 8 is a further partial longitudinal section corresponding generally to FIG. 6 but showing a modification in which an alternate side release means is provided for disengaging the latch mechanism assembly at projected position;

FIG. 9 is a partial longitudinal section showing the alternate side release means in FIG. 8 operated to disengage the latch at projected position;

.FIG. 10 is a further partial longitudinal section corresponding generally to FIG. 8 but showing a further modification in which a differently arranged alternate side release means is provided; and

FIG. 11 is a partial longitudinal section showing the alternate side release means in FIG. 10' operated to disengage the latch at projected position.

The writing instrument 10 shown in FIG. 1 as an illustrative embodiment of the present invention comprises a two-part barrel housing formed by a forward barrel portion 12 and a rear barrel portion :14, in which a writing or ballpoint and reservoir unit 16 is slidably arranged for projection forwardly from a retracted position, as seen in FIG. 1, to a projected writing position at a tapered writing end of the forward barrel portion 12, and in which the writing unit 16 is continuously biased rearwardly toward the retracted FIG. 1 position by a spring 18 seated at a rearwardly facing shoulder step 2 0 formed in the forward barrel portion 12 and bearing therefrom against a forwardly facing shoulder 22 formed exteriorly on the writing unit 16.

The forward barrel portion 12 is reduced in diameter and threaded exteriorly adjacent its rear end, as at 24, for assembly with the rear barrel portion 14 at a complementary internally threaded forward end thereof, and at which the rear barrel portion is covered by an exterior decorative sleeve 26 extending over a major portion of its length in the illustrated embodiment and in relation to which a pocket clip 26 is carried on the rear barrel portion 14 (compare FIGS. 1 and 2). When assembled in this manner, the forward barrel portion 12 is arranged with a central bore 28 thereof opening rearwardly in alignment with a central bore 30 of the rear barrel portion 14, which is rearwardly reduced in diameter to form a terminal bore 32 with an annular shoulder 34 facing forwardly at the juncture of the central and terminal bores 30 and 32.

The latch mechanism assembly provided according to t the present invention for the above described writing instrument comprises an assembly sleeve member 36, a latch member 38 and a plunger member 40 arranged in interlocked relation within the rear barrel portion 14. The assembly sleeve 36 is fixed within the central bore 30 of the rear barrel portion 14 with the rear end thereof abutting the forwardly facing annular shoulder 34 at the terminal bore 32 and with the interior cross section of the assembly sleeve member 36 smaller than that of the terminal bore 32. 'The assembly sleeve 36 may be fixed within the central bore 30 in any convenient manner, such as by forwardly tapered ridges 36' formed exteriorly on the assembly sleeve 36 for gripping tightly the central bore 30 when the sleeve 36 is pressed in place therein. Also, a cup member 42 may be pressed in place within the central bore 30 forwardly of the assembly sleeve 36 for further securing it in place and additionally providing for leading the rear end of the writing unit 16 readily into the forward end of the assembly sleeve 36 whenever the barrel portions 12 and 14 are to be assembled over the writing unit 16.

The assembly sleeve 36 is generally tubular in form for fixing within the central bore 30 in the above noted manner, and the forward end portion thereof has a pair of diametrically opposed longitudinal slots 44 and 46' formed therein; both of these slots 44 and 46 extending from the forward end of assembly sleeve 36 and terminating so as to form shoulders 48 and 50 that have a' slight forward inclination inwardly of the assembly sleeve 36. In addition, one longitudinal slot 46 extends rearwardly of the other slot 44 so that the respective shoulders 50 and 48 formed thereat are spaced longitudinally in correspondence with the extent to which the writing unit 16 must be shifted for retracted and projected positioning thereof.

The above mentioned generally tubular form of the assembly sleeve 36 is modified rearwardly of the longitudinal slots 44 and 46 by an inwardly stepped fiat wall portion 52 that is formed parallel to the diametric axis on which the slots 44 and 46 are opposed, and that is proportioned so that the reduced cross section of the assembly sleeve 36 at which this flat wall portion 52 is formed still constitutes a major circular segment, both internally and externally. It should also be noted again that while there is particular advantage in providing the assembly sleeve 36 as a separate component, for the reasons previously explained, the above described structure of the assembly sleeve 36 might alternatively be formed integrally in the rear barrel portion 14, if desired, to accommodate a latch member 38 and plunger member 40 arranged according to the present invention.

The latch member 38 of the present invention is of the type disclosed in the previously mentioned copending application Serial No. 631,771, filed December 31, 1956, now Patent Number 2,930,354 and is arranged in the manner described in that application for slidably floating within the sleeve member 36 lengthwise thereof and in fulcrumed relation thereto. For this purpose, the rear end of the latch member 38 is formed with rearwardly facing contact surfaces 54 and 56 that converge rearwardly to a point substantially on the longitudinal axis of the latch member 38 and extend forwardly to fulcrum portions 58 and 60 formed along the opposite edges of the intermediate body portion of latch member 38.

At its forward end, the latch member 38 is shaped to provide oppositely extending lateral arm portions 62 and 64 for latching engagement alternately at the shoulders 48 and 50 formed in the assembly sleeve 36 by the opposite longitudinal slots 44 and 46 therein, this alternate latching engagement being effected by selective rocking of the latch member 38 about the fulcrum portions 58 and 60 within the assembly sleeve 36 through the action of the plunger member 40 thereon as is described further below. In this connection it should be noted that the above mentioned lateral arm portions 62 and 64 might be longitudinally stepped on the latch member 38 for alternate retracted and projected latching engagement in longitudinal assembly sleeve slots 44 and 46 of equal length, if desired.

The latch member 38 is carried in the above noted manner within the assembly sleeve 36 so that its forward end is disposed at the rear end of the writing unit 16 for fulcrumed rocking in relation thereto as described above, while acting directly on the writing unit 16 for effecting the retracted and projected positioning thereof. In this connection, the forward face 66 of the latch member 38 is shaped with a' generally rounded configuration and is preferably formed on a bias (compare FIGS. 2 and'3) for facilitating the fulcrumed rocking action thereof at the rear end of the writing unit 16. Rearwardly of this rounded forward face portion 66, the latch member 38 is formed with a generally rectangular cross section, the edges of which are preferably somewhat rounded, but the opposite side faces of which are formed flat so that one of these side faces is adapted for riding at the flat wall portion 52 of the assembly sleeve 36 for positioning the latch member 38 against rotation within the assembly sleeve 36, while the other side face of the latch member 38 is formed with a relatively wide transverse groove 68 for interlocking assembly with the plunger member 40 in the manner to be described presently.

The plunger member 40 employed according to the present invention with the above described latch member 38 is formed with a cylindrical rear end portion 70 slidably arranged within the terminal bore 32 of the rear barrel portion 14 and proportioned for extending rearwardly therefrom so as to be accessible for manual depression therein. Forwardly of this rear end cylindrical portion 70, the plunger member 40 is reduced to an intermediate section 72 shaped for slidably fitting within the circular segment cross section of the assembly sleeve 36 at its rear end, and this intermediate plunger section 72 has forwardly facing contact surfaces 74 and 76 formed thereon in opposing operative relation with respect to the latch member contact surfaces 54 and 56; the operative relation of these plunger and latch member contact surfaces being such as to engage a given plunger member contact surface with a related latch member contact surface upon each depression of the plunger member 40, and by such engagement to exert a rocking force on the fulcrumed latch member 38 incident to longitudinal movement of the plunger and latch members 40 and 38 within the assembly sleeve 36 for shifting the writing unit 16 between retracted and projected positions, as is illustrated in FIGS. 4, 5, 6 and 7 and described further below.

For interlocking assembly with the latch member 38, as previously mentioned above, the plunger member 40 is further formed with a leg portion 78 extending forwardly beyond the plunger member contact surfaces 74 and 76 and disposed at the side face of the latch member 38 in which the transverse groove 68 is formed and a relatively narrow transverse retaining lug 80 is formed on the leg portion 78 for disposition within the transverse latch member groove 68. By this arrangement, the latch member 38 and plunger member 40 are interlocked within the assembly sleeve 36, while the latch member engages one or the other of the longitudinal slots 44 or 46 at the forward end of the assembly sleeve 36, and

the rear end cylindrical plunger portion 70 has a cross section such as to bottom at the rear end of the assembly sleeve 36, so as to provide a completely interlocked latch mechanism assembly which may be installed as a unit within the rear barrel portion 14, and which remains as an interlocked assembly therein irrespective of any disassembly of the writing instrument otherwise.

It has previously been noted that the structure embodied in the assembly sleeve 36 might alternatively be formed as an integral part of the rear barrel portion 14 while retaining the above described interlocked assembly arrangement of the latch member 38 and plunger member 40 in exactly the same manner. It should also be noted that the relatively wide transverse groove 68 in the latch member 38 might alternatively be formed in the leg portion 78 of the plunger member 40, and the plunger member transverse lug 80 on the latch member 38, to provide for the interlocking assembly of these elements. In this connection, it might be further noted that the plunger member transverse lug 80 is shaped with a rearwardly directed retaining face that is formed at a right angle to the leg portion 78, while the other face of the lug 80 is inclined forwardly, and the rear end of the latch member 38 at the adjacent side face is beveled. This particular arrangement makes it possible when the assembly sleeve 36, the latch member 38 and plunger member 40 are formed of molded plastics that are relatively yieldable, such as nylon, to install the latch member 38 and plunger member 40 at the opposite ends of the assembly sleeve 36 and by a slight amount of pressure to snap the plunger member lug 80 into place within the latch member transverse groove 68 for assembling readily the latch mechanism of the present invention in the above noted manner.

It should also be mentioned that the relatively wide transverse latch member groove is proportioned in width and in depth with respect to the relatively narrow plunger member transverse lug 80 so as to allow the necessary operating movement of the latch member 38 with respect to the plunger member 40 without bringing the plunger lug 86 into contact with any surface of the groove 68, such surface contact occurring only when necessary to maintain the latch mechanism assembly interlocked in instances such as when the rear barrel portion 14 is removed from the forward barrel portion 18 for access to the writing unit 16, and at which time the normal rearward pressure on the latch member 38 by the rearwardly biased writing unit 16 would be removed.

FIGS. 4, 5, 6 and 7 illustrate the operation of the above described latch mechanism assembly of the present invention during retracted and projected positioning of the writing unit 16. In FIG. 4, the writing unit 16 and latch mechanism are shown in retracted position, the lateral arm portion 64 of the latch member 38 being seated at the Shoulder 50 in the longitudinal assembly sleeve slot 46, and the rearward pressure exerted through the writing unit 16 by the biasing spring 18 therefor having resulted in positioning the latch member 38 with the fulcrum portion 58 thereof bearing against the adjacent wall of the assembly sleeve 36, so as to dispose the latch member contact surface 54 in opposed relation with respect to the plunger contact surface 74. Upon depression of the plunger member 40 under these circumstances, as seen in FIG. 5, the result is to apply a rocking force on the latch member 38 about the fulcrum portion 58 thereof, through the opposed contact surfaces 54 and 74, so as to rock the latch member 38 in the direction to engage the arm portion 62 thereof at the projected position latching shoulder 48 in the assembly sleeve slot 44 upon longitudinal shifting to projected position as seen in FIG. 6.

Upon reaching the FIG. 6 projected position, the subsequent release of the plunger member 40 allows the rearward bias on the writing unit 16 again to position the latch member 38 within the assembly sleeve 36, but

this time with the opposite fulcrum portion 60 thereof bearing against the opposite wall portion of the assembly sleeve 36, so as to dispose the latch member contact surface 56 this time in opposed relation to the plunger member contact surface 76 and thereby reset the latch member 38 with respect to the plunger member 40 so that upon a succeeding plunger member depression the latch member 38 is oppositely rocked about the fulcrum portion 60 for disengagement from the projected position latching shoulder 48, as seen in FIG. 7, and return to the FIG. 4 retracted position.

FIGS. 8, 9, l0 and 11 illustrate modified embodiments of the present invention in which an alternate side release means is provided to disengage the latch member 38 at projected position for return to retracted position. FIG. 8 shows a latch mechanism assembly of the above described type arranged at projected position with a lateral opening 82 formed in a rear barrel portion 14' through which the latch member arm portion 62 is accessible when engaged at the projected position latching shoulder 48 formed in the assembly sleeve slot 44. In addition, a manually operable release member 84 is carried exteriorly on the rear barrel portion 14, suitably by a pocket clip 86, with an inwardly extending finger portion 88 thereof disposed for depression through the lateral opening 82 to disengage the projected latch member 38 as illustrated in FIG. 9.

FIG. 10 shows a further modified embodiment in which the intermediate section 72 of the plunger member 40 is necked rearwardly so as to form a rearwardly and outwardly facing cam surface 90 thereon; in which the rear barrel portion 14 is formed with a lateral opening 92. through which this cam surface 90 is accessible when the plunger member 40 has been operated to engage the latch member 38 at projected position; and in which an alternate side release member 94 is again carried exteriorly on the rear barrel portion 14, suitably by a pocket clip structure such as is illustrated at 96, so as to provide for extension of a finger portion 98 of the release member 94 inwardly through the lateral opening 92 to bear at the plunger cam surface 90 and thereby operate the plunger member 40 upon depression of the side release member 24 to disengage the latch member 38 at projected position, as illustrated in FIG. 11, for return to retracted position.

The present invention has been described in detail above for purposes of illustration only and is not intended to be limited by this description or otherwise except as defined in the appended claims.

I claim:

1. A ball point writing instrument comprising a barrel, a writing unit slidably arranged within said barrel for retracted and projected positioning with respect thereto, means continuously biasing said writing unit rearwardly within said barrel toward retracted position, and means for alternately positioning said writing unit in retracted and projected relation with respect to said barrel; said positioning means including a rockable latch member slidably floating in fulcrumed relation at the rear end of said writing unit and within said barrel and having rearwardly facing first and second contact surfaces disposed on opposite sides thereof and latching portions longitudinally spaced therefrom, means within said barrel engageable by said latching portions upon rocking thereof for latching said writing unit alternately at said retracted and projected positions against the force of said biasing means, and a depressible plunger member slidably carried at the rear end of said barrel and having forwardly facing first and second contact surfaces disposed on opposite sides thereof in opposing operative relation to said latch member contact surfaces, the operative relation of said plunger and latch member contact surfaces being such that said first and second contact surfaces of said plunger are successively engageable with respective first and second latch member contact surfaces upon successive plunger depressions and by such engagement to exert a rocking force on said fulcrumed latch member incident to longitudinal movement of said plunger and latch members within said barrel for shifting said writing unit between retracted and projected positions, said plunger member having a leg portion extending forwardly beyond the contact surfaces thereon and disposed at a side face of said latch member, and said plunger member leg portion and latch member side face having a relatively narrow transverse retaining lug formed on one and a relatively wide transverse groove formed on the other for receiving said retaining lug and thereby interlocking said plunger and latch members in assembled relation within said barrel in a manner to permit opposite rocking of said latch member relative to said plunger member when a given plunger member contact surface engages a related latch member contact surface for shifting said writing instrument between retracted and projected positions.

2. A ball point writing instrument as defined in claim 1 and further characterized in that said barrel is formed with a lateral opening and the means within said barrel engageable by said latch member for latching said writing unit at projected position is formed adjacent said lateral opening in said barrel through which said latch member is accessible from the exterior of said barrel when engaged thereat, and a manually operable member is carried exteriorly on said barrel at said lateral opening for depression therein to disengage said latch member at said projected position.

3. A ball point writing instrument as defined in claim 1 and further characterized in that said plunger member is necked within said barrel rearwardly of said plunger contact surfaces so as to form a rearwardly and outwardly facing cam surface thereon, said barrel is formed with a lateral opening through which said cam surface is accessible when said latch member is engaged for latching said writing unit at projected position, and a manually operable member is carried exteriorly on said barrel at said lateral opening for depression therein to actuate said plunger member through said cam surface for disengaging said latch member at said projected position.

4. In a writing instrument having a barrel, a depressible plunger disposed for longitudinal sliding within said barrel and projecting beyond the rear barrel end, a writing element biased rearwardly within said barrel and slidably disposed therein to shift longitudinally between projected and retracted positions with respect to the forward barrel end, a laterally rockable and longitudinally movable latch member disposed within said barrel rearwardly of said writing element and forwardly of said plunger, said latch member being unattached to the writing element and having rearwardly facing first and second contact areas disposed on opposite side thereof and latching portions spaced longitudinally therefrom, said plunger having forwardly facing first and second contact areas disposed on the opposite sides thereof and disposed in opposing operative relation to said latch member contact areas, said first and second contact areas of said plunger being successively engageable with respective first and second latch member contact areas upon successive plunger depressions thereby laterally rocking said latch member alternately in opposite directions, and means disposed within said barrel for releasably engaging a latching portion of said latch member upon rocking thereof for alternately positioning said writing element at said projected and retracted positions, the improvement of said plunger member being provided with a leg portion extending forwardly beyond the contact areas thereon and disposed at a side face of said latch member, and said plunger member leg portion and latch member side face having a relatively narrow transverse retaining lug formed on one and a relatively wide transverse groove formed on the other for receiving said retaining lug and thereby interlocking said plunger and latch members in assembled relation within said barrel in a manner to permit rocking of said latch member relative to said plunger member when a given plunger member contact area engages a related latch member contact area for shifting said writing element between retracted and projected positions.

References Cited in the file of this patent UNITED STATES PATENTS 2,715,888 Liguori Aug. 23, 1955 2,800,882 Smith July 30, 1957 2,865,331 Marcotte Dec. 23, 1958 2,929,360 Smith Mar. 22, 1960 2,930,354 Lockwood Mar. 29, 1960 2,930,355 Bollerup Mar. 29, 1960 2,930,356 Liguori Mar. 29, 1960 FOREIGN PATENTS 430,704 Italy Feb. 18, 1948 1,086,929 France Aug. 18, 1954 1,091,302 France Oct. 27, 1954 1,127,686 France Aug. 13, 1956 203,793 Australia Oct. 16, 1956 

